1. Field of the Invention
Exemplary embodiments described herein relates to a MISFET which is formed on a (110) surface of an SiGe layer and which has a current direction in a <−110> direction and which has uniaxial strain.
2. Description of the Related Art
There have heretofore been proposed micro metal insulator semiconductor field effect transistors (MISFETs) with high drive current as follows: a fine-wire form MISFET using, as channels, Si, Ge and SiGe that are formed on an Si (100) substrate by an oxidation or etching process; and a FinMISFET.
One example is a pMOSFET (e.g., refer to T. Irisawa; IEDM 2005, p. 457) wherein a (100) surface of a totally strained silicon-germanium-on-insulator (SGOI) layer produced by a Germanium condensation technique is mesa-processed into a Fin form long in a <110> direction, and a (110) surface of the side surface of the Fin is used as a uniaxial strain channel. Another example is a uniaxial strain channel MOSFET (e.g., refer to T. Irisawa; IEDM 2006, p. 725) wherein a (100) surface of a strained-silicon-on-insulator (SSOI) substrate is used and thus Fin-processed to be long in a <110> direction.
In the above-mentioned examples, a Fin structure is produced on the (100) surface of the substrate, and in the process of this production, elastic uniaxial stress relaxation is used to obtain the uniaxial strain channel. It is thus difficult to produce MISFETs for both p and n on the same substrate and construct a complementary MISFET.
JP-A 2007-515808 (KOHYO) has also proposed a CMOSFET wherein a bulk strain-relaxed SiGe stacked substrate is formed on a bulk Si substrate, on which there are an Si-nMOS region having biaxial tensile strain and an SiGe or Ge-pMOS region having biaxial compressive strain. However, this JP-A publication shows no descriptions of uniaxial strain and the shape of a channel and no particular specification of surface orientation.
JP-A 2000-286418 (KOKAI) has also proposed a CMOSFET wherein there are an Si-nMOS region having biaxial tensile strain and an SiGe or Ge-pMOS region having biaxial compressive strain on an SGOI or on a bulk strain-relaxed SiGe stacked substrate. However, this publication shows no descriptions of uniaxial strain and the shape of a channel either.
When channel directions are taken in a [−110] direction with high mobility in both p- and n-channel MISFETs, it is difficult to achieve high mobility on the same (100) substrate for both the p- and n-channel types.
There has thus been a demand for a semiconductor device with high mobility in which both p- and n-channel types are formed on the same substrate, and for a manufacturing method thereof.